Types of Oysters

Oysters are bivalves which feed by filtering algae and other nutrients from the salt water in which they live. It has been estimated that an oyster can filter as much as one million tonnes of suspended material (mostly phytoplankton) in its lifetime.

Commercially, Australia produces three main types of oysters – two ‘cupped’ (Pacific and Sydney Rock);   and one  ‘flat’ (Angasis).     The Angasi and Sydney Rock oysters are natives to Australia.

Pacific Oysters (Crassostrea gigas)

These are also referred to as Japanese Oysters, so named due to them being native to Japan. Pacific Oysters were introduced into Tasmania in the late 1940’s, and are now also grown in South Australia and limited areas in New South Wales (Port Stephens, Hawkesbury River and Georges River regions).  They have been banned in a number of areas of New South Wales, all of Queensland, Victoria and Western Australia due to their potential threat to the native Rock Oyster.

Pacific Oysters grow relatively quickly and are generally ready for market after 1.5 to 2 years; but can be ready as soon as 10 months.  For best growth they require relatively clear water with salinity less than 35ppt, pH between 6.75 to 8.75; temperatures between 10 to 18 degrees Celsius;  and low concentrations of metal compounds.

The shell colour ranges from muddy brown to light grey and contains some purple streaks and spots.
The meat is generally creamy white with a dark fringe around the mantle at times.
The colour of the meat and shell can vary depending on the region and season.
Generally Pacific oysters have a mild, sweet flavour, with a firm, plump texture.


Sydney Rock Oysters (Saccostrea glomerata sp.)

These oysters are native to Australia and endemic to New South Wales. They are also referred to as Western Rock Oysters where farmed in Albany, Western Australia. They can be distinguished from Pacific Oysters by their triangular-shaped, smoother shells; black markings on the inside edge of the round end; and the pale edge (mantle) of their actual meat.

They are generally smaller (6-8 cm), and milder tasting than the Pacific Oysters; and generally take about twice as long to grow (3 to 4 years). For best growth they require relatively clear water, with salinity less than 35ppt; pH between 6.75 to 8.75; temperatures between 14 to 30 degrees Celsius, and low concentrations of metal compounds.


Angasi Oysters (Ostrea angasi)

These are also referred to as Native, Mud or Port Lincoln Oysters and endemic to areas of southern Australia. They are now quite rare. There has been a resurgence of popularity in recent times, especially in the menus of top restaurants around Australia. They are grown on the southern coast of New South Wales around Bermagui and Merimbula; and in Tasmania.
As a flat oyster, they have quite a different flavour and texture to the Pacifics and Rocks; and are sometimes mistakenly referred to as Belons (referring to the European Oyster to which they are related). They are also related to the Bluff Oysters of New Zealand.


Marine Culture specialises in the production of Pacific Oysters.